A Russian investigator has said grenades fired by surrounding Russian forces could have triggered the Beslan school bloodbath in September 2004. Yuri Savelyev's conclusions contradict the official view that bombs planted by the hostage-takers in the school gym went off just before the gun battle. Mr Savelyev is a member of the Russian parliamentary commission investigating the siege, in which 331 people died. Mr Savelyev, a weapons and explosives expert, said that during the investigation, he discovered that the consequences of those blasts could not at all be explained by the explosions of the home-made devices installed by the rebels". The head of the commission, Stanislav Kesayev, said he had confidence in Mr Savelyev's conclusions. "He had more resources than our commission. He relied on his own knowledge as a weapons specialist and mathematician," Mr Kesayev told the radio. For weeks after the siege Russian officials had denied the use of flamethrowers.